Whether it was socialist or not is another interesting question. Some would say that it wasn't, on the basis that real socialism cannot be non-democratic, as that precludes meaningful common ownership of property - and Bolsheviks were consistently anti-democratic very early on, what with shutting down the Constituent Assembly, instituting kombeds to suppress local councils that were in opposition to them, and even explicitly writing a formula into the constitution that made urban (i.e. predominantly worker) councils have 5x voting power of rural (i.e. predominantly peasant) councils. But even ignoring that, it's hard to reconcile socialism with suppression of trade unions in politics (https://en.wikipedia.org/wiki/Workers%27_Opposition) - which also happened under Lenin.
Then again, if we take pure Marxism, a socialist revolution was supposed to be impossible in Russia anyway, simply because proletariat was not the majority of the population. Lenin and co had to do a lot of handwaving to explain that away, and one could reasonably claim that the result deviated sufficiently from what Marx had in mind that it shouldn't really be lumped together.
"It was a disintegration of historical Russia under the name of the Soviet Union," Putin said of the 1991 breakup, in comments aired on Sunday as part of a documentary film called "Russia. New History", the RIA state news agency reported.
"We turned into a completely different country. And what had been built up over 1,000 years was largely lost," said Putin, saying 25 million Russian people in newly independent countries suddenly found themselves cut off from Russia, part of what he called "a major humanitarian tragedy".
In any case Marxism was pretty much always window dressing in the USSR, anyway, post-Stalin. And in its final years the USSR was ditching any signficant pretext of Marxist-inspired socialism altogether. If it could have survived would probably would have evolved into a hybrid capitalist autocracy like modern China -- with significant state planning characteristics, but with the ideological mumbo-jumbo dialed down to a bare minimum.